1. Technical Field
The subject disclosure relates to minimally invasive surgical procedures and apparatus, and more particularly to an instrument and method for performing surgery associated with the thoracic cavity.
2. Background of Related Art
The diagnosis and treatment of coronary disease and related conditions typically requires access to the heart, blood vessels and associated tissue. Such procedures include cardiopulmonary bypass, valve repair and replacement, and treatment of aneurysms. Access to the patient""s thoracic cavity may be achieved by a large longitudinal incision in the chest. This procedure, referred to as a median sternotomy, requires a saw or other cutting instrument to cut the sternum and allow two opposing halves of the rib cages to be spread apart. U.S. Pat. No. 5,025,779 to Bugge discloses a retractor which is designed to grip opposite sternum halves and spread the thoracic cavity apart. The large opening which is created by this technique enables the surgeon to directly visualize the surgical site and perform procedures on the affected organs. However, such procedures that involve large incisions and substantial displacement of the rib cage are often traumatic to the patient with significant attendant risks. The recovery period may be extended and is often painful. Furthermore, patients for whom coronary surgery is indicated may need to forego such surgery due to the risks involved with gaining access to the heart.
U.S. Pat. No. 5,503,617 to Jako discloses a retractor configured to be held by the surgeon for use in vascular or cardiac surgery to retract and hold ribs apart to allow access to the heart or a lung through an operating window. The retractor includes a rigid frame and a translation frame slidably connected to the rigid frame. Lower and upper blades are rotatably mounted to the rigid frame and the translation frame respectively.
Once access to the thoracic cavity has been achieved, surgery on the heart may be performed. Such procedures typically require that the heart beat be arrested while maintaining circulation throughout the rest of the body. Cardioplegic fluid, such as potassium chloride (KCl) is delivered to the blood vessels of the heart to paralyze the myocardium. As disclosed in WO 95/15715 to Sterman et al. for example, cardioplegic fluid is infused into the myocardium through the coronary arteries by a catheter inserted into the ascending aorta. Alternatively, cardioplegic fluid is infused through the coronary veins in a retrograde manner by a catheter positioned in the interior jugular vein accessed at the patient""s neck. Such procedures require the introduction of multiple catheters into the blood vessels adjacent the heart, which is a complicated procedure requiring that the desired vessels be properly located and accessed. The progression of the guide wires and catheters must be closely monitored to determine proper placement. Furthermore, the introduction of catheters forms punctures in the blood vessels that must be subsequently closed, and there is an increased risk of trauma to the interior walls of the vessels in which the catheters must pass.
Therefore, a need exists for an apparatus and procedure which provides access to the thoracic cavity without causing extensive trauma to the patient. A procedure is needed to at least locally stabilize a predetermined area of the heart surface that is relatively simple to perform and incorporates instruments that are simple and reliable. Furthermore, an apparatus and procedure is needed which provides a stable framework for supporting additional instruments which may be used during these procedures.
The present disclosure is directed to instruments for and methods of surgery. A retractor is provided which has a substantially planar base defining an opening for overlying an operative site on a patient, and at least one retractor blade slidably mounted to the base.
The base is positioned on the patient such that the opening therein overlies the operative site, and the operative site is percutaneously accessed through the opening. Obstructing tissue is retracted with one or more retractor blades to create an opening to provide access for the surgical procedure. A surgical instrument is provided which is engageable with the base and operable at the operative site. A surgical procedure is carried out through the opening in the base with the surgical instrument.
In a preferred embodiment, the retractor blade includes a ratchet assembly, and the method includes fixing the position of the retractor blade with respect to the base with the ratchet assembly.
The retractor blade may also include an integral blowing, irrigation or suction assembly operably positioned adjacent the blade to remove blood, fluid, etc. In another embodiment, a light assembly may be incorporated to illuminate designated portions of the surgical field.
A heart manipulator is disclosed for use in conjunction with the retractor and is releasably mountable on the base. The heart manipulator assists in atraumatically holding and positioning the heart to facilitate access thereto. In a preferred embodiment the heart manipulator includes a loop shaped frame which supports a mesh cradle.
A heart stabilizer instrument is also disclosed. This instrument is preferably configured to be mounted to the base portion and has a heart contacting surface. The heart may be contacted with the heart contacting surface to stabilize the position of a predetermined portion of the heart surface. A heart stabilizer instrument may be provided which is mounted to the base portion and movable with respect thereto. The predetermined portion of the heart surface is substantially stabilized by applying pressure thereto. In a preferred embodiment, the heart stabilizer instrument includes structure configured to compress the coronary artery, and the step of stabilizing a predetermined portion of the heart surface includes applying pressure to the coronary artery with the heart stabilizer instrument. The position of the heart stabilizing device may be locked with respect to the base.
The base may be provided to the hospital and/or surgeon in a kit form including one or more retractors. The kit may also advantageously include a heart manipulator and/or heart stabilizing device.
The surgical method may further include providing an actuator associated with the retractor blade and configured to effect linear movement of the retractor blade.
These and other features of the surgical retractor and method for heart surgery will become more readily apparent to those skilled in the art from the following detailed description of preferred embodiments of the subject disclosure.